Basic Carabiner Use and Safety

Carabiners are an integral part of a comprehensive fall protection system. They are built to withstand extreme forces, and are light so as to add minimal weight to a worker’s gear. Different tasks require different kinds of carabiners. The variables that typically distinguish styles include shape, gate type, strength, weight, and size.

Carabiners come in various types—most commonly resembling either a pear or the letter D—and feature either a “gate” or a screw type closure. Gate (non-locking) carabiners allow the user to push open the spring-loaded gate and place a line or strap within the loop. Once inside, the gate closes and cannot be opened by pressure from the opposing direction. Screw and twist-lock types (locking) carabiners have an additional sleeve to secure the gate. Twist lock types may lock automatically, while screw types are threaded (as the name indicates) and must be locked manually.

PROPER USE

A carabiner’s strength rating assumes proper use of the device. Improper use will stress the carabiner and decrease its strength. Workers should check gate action with each use to ensure smooth and proper function. Workers should be sure the nose and hinge of the carabiner operate smoothly and without obstructions.

Workers should not allow the rope to run against the sleeve of a locking carabiner. Loads should only be placed along the major axis (lengthwise). A carabiner loaded along the minor (widthwise) axis can fail in a fall.

It should be noted that gate-open strength is less than half of a carabiner’s gate-closed strength. When using non-locking carabiners, workers should avoid setups in which a rope can cross back and open a gate. With both straight- and bent-gate carabiners, a protruding nose can catch and open a gate. Locking carabiners should be used at all critical points. Workers must check that locking carabiners are properly locked with each use.

MEASURING CARABINER STRENGTH

Because a falling worker accelerates under the pull of gravity, carabiner strengths are measured in kiloNewtons (kNs), a unit of force (mass times acceleration). For conversion purposes, 1 kN is approximately equal to 225 lbs. of force. Rigid Lifelines carabiners feature are certified to meet ANSI Z359.12-2009 and CSA Z259.12-01. Each carabiner sold by Rigid Lifelines is proof load tested to 3,600 Lbs. (16kN) in the major axis. Spring loaded twist-lock gate makes for quick connection and locking.

MAINTENANCE

Before each use, carabiners should be checked for signs of wear, damage, or fatigue. Locking mechanisms should be inspected to ensure smooth operation and integrity. The carabiner should be inspected visually for any signs of stress—including bending, corrosion, excessive wear, extreme temperature stress, or cracking. Damaged or worn carabiners should NOT be used.

Contact your distributor or manufacturer representative to help you select the right carabiners for your fall protection system.